Displaying publications 1 - 20 of 243 in total

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  1. Hena S, Znad H, Heong KT, Judd S
    Water Res, 2018 01 01;128:267-277.
    PMID: 29107911 DOI: 10.1016/j.watres.2017.10.057
    Dairy cattle treated wastewaters are potential resources for production of microalgae biofuels. A study was conducted to evaluate the capability of Arthrospira platensis cultivated in dairy farm wastewater for biodiesel production. The biomass of Arthrospira platensis was found to be 4.98 g L-1 and produced 30.23 wt% lipids to dry biomass cultivated in wastewater which was found nitrogen stressed in photo bioreactor. The extracted lipid displayed a suitable fatty acid profile for biodiesel, although the content of linolenic acid was found a little higher than the standard EN14214. It was found that nitrogen stressed medium increase the total lipid content but temperature and intensities of light were the most important factors to control the quantity of linolenic acid and hence the quality of biodiesel, while the optimum CO2 helped to achieve maximum biomass and triacylglycerols. The Arthrospira platensis offer a good option for the treatment of wastewater before final discharge.
    Matched MeSH terms: Microalgae
  2. Kok YY, Chu WL, Phang SM, Mohamed SM, Naidu R, Lai PJ, et al.
    J Zhejiang Univ Sci B, 2011 May;12(5):335-45.
    PMID: 21528487 DOI: 10.1631/jzus.B1000336
    This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus, Synechococcus elongatus, and Spirulina platensis against Epstein-Barr virus (EBV) in three Burkitt's lymphoma (BL) cell lines, namely Akata, B95-8, and P3HR-1. The antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction (PCR) technique. The methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in reducing cell-free EBV DNA (EC(50)<0.01 µg/ml) with a high therapeutic index (>28000). After fractionation by column chromatography, the fraction from Synechococcus elongatus (SEF1) reduced the cell-free EBV DNA most effectively (EC(50)=2.9 µg/ml, therapeutic index>69). Upon further fractionation by high performance liquid chromatography (HPLC), the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA (EC(50)=1.38 µg/ml, therapeutic index>14.5). This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.
    Matched MeSH terms: Microalgae/chemistry*
  3. Cheah WY, Ling TC, Juan JC, Lee DJ, Chang JS, Show PL
    Bioresour Technol, 2016 Sep;215:346-56.
    PMID: 27090405 DOI: 10.1016/j.biortech.2016.04.019
    Greenhouse gas emissions have several adverse environmental effects, like pollution and climate change. Currently applied carbon capture and storage (CCS) methods are not cost effective and have not been proven safe for long term sequestration. Another attractive approach is CO2 valorization, whereby CO2 can be captured in the form of biomass via photosynthesis and is subsequently converted into various form of bioenergy. This article summarizes the current carbon sequestration and utilization technologies, while emphasizing the value of bioconversion of CO2. In particular, CO2 sequestration by terrestrial plants, microalgae and other microorganisms are discussed. Prospects and challenges for CO2 conversion are addressed. The aim of this review is to provide comprehensive knowledge and updated information on the current advances in biological CO2 sequestration and valorization, which are essential if this approach is to achieve environmental sustainability and economic feasibility.
    Matched MeSH terms: Microalgae
  4. Hussein HA, Maulidiani M, Abdullah MA
    Heliyon, 2020 Oct;6(10):e05263.
    PMID: 33102866 DOI: 10.1016/j.heliyon.2020.e05263
    Heavy metal pollution has become a major concern globally as it contaminates eco-system, water networks and as finely suspended particles in air. In this study, the effects of elevated silver nanoparticle (AgNPs) levels as a model system of heavy metals, in the presence of microalgal crude extracts (MCEs) at different ratios, were evaluated against the non-cancerous Vero cells, and the cancerous MCF-7 and 4T1 cells. The MCEs were developed from water (W) and ethanol (ETH) as green solvents. The AgNPs-MCEs-W at the 4:1 and 5:1 ratios (v/v) after 48 and 72 h treatment, respectively, showed the IC50 values of 83.17-95.49 and 70.79-91.20 μg/ml on Vero cells, 13.18-28.18 and 12.58-25.7 μg/ml on MCF-7; and 16.21-33.88 and 14.79-26.91 μg/ml on 4T1 cells. In comparison, the AgNPs-MCEs-ETH formulation achieved the IC50 values of 56.23-89.12 and 63.09-91.2 μg/ml on Vero cells, 10.47-19.95 and 13.48-26.61 μg/ml on MCF-7; 14.12-50.11 and 15.13-58.88 μg/ml on 4T1 cells, respectively. After 48 and 72 h treatment, the AgNPs-MCE-CHL at the 4:1 and 5:1 ratios exhibited the IC50 of 51.28-75.85 and 48.97-69.18 μg/ml on Vero cells, and higher cytotoxicity at 10.47-16.98 and 6.19-14.45 μg/ml against MCF-7 cells, and 15.84-31.62 and 12.58-24.54 μg/ml on 4T1 cells, respectively. The AgNPs-MCEs-W and ETH resulted in low apoptotic events in the Vero cells after 24 h, but very high early and late apoptotic events in the cancerous cells. The Liquid Chromatography-Mass Spectrometry-Electrospray Ionization (LC-MS-ESI) metabolite profiling of the MCEs exhibited 64 metabolites in negative ion and 56 metabolites in positive ion mode, belonging to different classes. The microalgal metabolites, principally the anti-oxidative components, could have reduced the toxicity of the AgNPs against Vero cells, whilst retaining the cytotoxicity against the cancerous cells.
    Matched MeSH terms: Microalgae
  5. Djearamane S, Lim YM, Wong LS, Lee PF
    PeerJ, 2019;7:e7582.
    PMID: 31579572 DOI: 10.7717/peerj.7582
    Background: Zinc oxide nanoparticles (ZnO NPs) are widely used in household and cosmetic products which imply an increased releasing of these particles into the environment, especially aquatic ecosystems, resulting in the need of assessing the potential toxic effects of ZnO NPS on the aquatic organisms, particularly on microalgae which form the base for food chain of aquatic biota. The present study has investigated the dose- and time-dependent cellular accumulation and the corresponding cytotoxic effects of increasing concentrations of ZnO NPs from 10-200 μg/mL on microalga Haematococcus pluvialis at an interval of 24 h for 96 h.

    Methods: The scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) was used to qualitatively detect the cellular accumulation of ZnO NPs in algal cells, while inductively coupled plasma optical emission spectrometry (ICP OES) was performed to quantify the cell associated-zinc in algal cells. The percentage of cell death, reduction in algal biomass, and loss in photosynthetic pigments were measured to investigate the cytotoxic effects of ZnO NPs on H. pluvialis. Extracellular and intracellular changes in algal cells resulted from the treatment of ZnO NPs were demonstrated through optical, scanning, and transmission electron microscopic studies.

    Results: SEM-EDX spectrum evidenced the accumulation of ZnO NPs in algal biomass and ICP OES results reported a significant (p < 0.05) dose- and time-dependent accumulation of zinc in algal cells from 24 h for all the tested concentrations of ZnO NPs (10-200 μg/mL). Further, the study showed a significant (p < 0.05) dose- and time-dependent growth inhibition of H. pluvialis from 72 h at 10-200 μg/mL of ZnO NPs. The morphological examinations revealed substantial surface and intracellular damages in algal cells due to the treatment of ZnO NPs.

    Discussion: The present study reported the significant cellular accumulation of ZnO NPs in algal cells and the corresponding cytotoxic effects of ZnO NPs on H. pluvialis through the considerable reduction in algal cell viability, biomass, and photosynthetic pigments together with surface and intracellular damages.

    Matched MeSH terms: Microalgae
  6. Foo SC, Khoo KS, Ooi CW, Show PL, Khong NMH, Yusoff FM
    Front Bioeng Biotechnol, 2020;8:546067.
    PMID: 33553111 DOI: 10.3389/fbioe.2020.546067
    The ever-expanding human population puts tremendous pressure on global food security. With climate change threats lowering crop productivity and food nutritional quality, it is important to search for alternative and sustainable food sources. Microalgae are a promising carbon-neutral biomass with fast growth rate and do not compete with terrestrial crops for land use. More so, microalgae synthesize exclusive marine carotenoids shown to not only exert antioxidant activities but also anti-cancer properties. Unfortunately, the conventional method for fucoxanthin extraction is mainly based on solvent extraction, which is cheap but less environmentally friendly. With the emergence of greener extraction techniques, the extraction of fucoxanthin could adopt these strategies aligned to UN Sustainable Development Goals (SDGs). This is a timely review with a focus on existing fucoxanthin extraction processes, complemented with future outlook on the potential and limitations in alternative fucoxanthin extraction technologies. This review will serve as an important guide to the sustainable and environmentally friendly extraction of fucoxanthin and other carotenoids including but not limited to astaxanthin, lutein or zeaxanthin. This is aligned to the SDGs wherein it is envisaged that this review becomes an antecedent to further research work in extract standardization with the goal of meeting quality control and quality assurance benchmarks for future commercialization purposes.
    Matched MeSH terms: Microalgae
  7. Loke, C.Y., Nur Hidayah, M.S., Mohd Fadhli, M.F., Teo, SK, Nor Hidayah, A.G., Yasmin Anum, M.Y., et al.
    Medicine & Health, 2010;5(1):1-12.
    MyJurnal
    Chlorella vulgaris, a unicellular microalgae, produces many intracellular phytochemicals namely carotenoids, tocopherols, ubiquinone and protein. Skin ageing which is induced by oxidative stress involves decreased extracellular matrix synthesis and increased expression of enzymes that degrade the collagenous matrix. The objective of this study was to determine the effect of C. vulgaris on the expression of genes encoded for collagen (COL) and matrix metalloproteinases (MMPs) which are involved in skin ageing. Human diploid fibroblasts (HDFs) were obtained from circumcision foreskin of 8-12 year-old boys. HDFs were cultured into 3 groups: untreated control cells, cells with stress-induced premature senescence (SIPS; cells were induced with H2O2 at passage 6 for 2 weeks) and SIPS treated with C. vulgaris (prolonged C. vulgaris treatment started at passage 4 and combined treatment with H2O2 at passage 6 for 2 weeks). Senescence-associated ß-galactosidase (SA ß-gal) was determined using senescent cells histochemical staining kit (Sigma, USA). Expression of COLI, COLIII, COLIV, MMPI, MMPII and MMPIII genes was quantitatively analysed with real-time RT-PCR method (iScript™ One Step real-time PCR with SYBR® Green; Biorad). HDFs treated with H2O2 (SIPS) exhibited senescent morphological features of flattening and enlarged with increased expression of SA ß-gal (p
    Matched MeSH terms: Microalgae
  8. Tevan, R., Jayakumar, Saravanan, Mohd Hasbi Ab. Rahim, Maniam, Gaaty Pragas, Govindan, Natanamurugaraj
    MyJurnal
    The world is facing a problem regarding the use of petroleum fuels that has led to a search for a suitable alternative fuel source. Researchers have come up with the idea of producing biofuel to overcome this problem. In this study, microalgae were explored as a high potential feedstock to produce biofuel. In order to produce a large quantity of biofuel with low cost at a short time, the manipulation of nutrients is a factor in microalgae cultivation. In this study, Iron (II) Chloride (FeCl2) was added to the nutrients to initiate a stressful condition during growth which contributes to the produce of lipid. Isolated microalgae species were identified as Scenedesmus sp. During mass cultivation, the microalgae cultures were scaled up to 2 L of culture. Three flasks of microalgae culture were labelled with S1, S2, and S3. Flask S1 acts as a control without the addition of FeCl2, while another two flasks acted as experimental flasks. Flask S2 was supplemented with 0.5 mg FeCl2 while Flask S3 was supplemented with 1.0 mg of FeCl2. With the addition of Iron (II) Chloride, microalgae entered a stationary phase at day 9 and day 10 as compared to the control flask which enters the stationary phase at day 7. This also affects the dry weight. Flask 3 produces 0.8658 g of microalgae powder compared to Flask 1 and 2 which produced 0.4649 g and 0.5357 g respectively. Lipid analysis was done by using GCMS and GCFID. Flask 3 produced various types of fatty acids which can be used for biodiesel production compared to other cultivates. In Flask 1, docosanoic acid which is a saturated fatty acid was detected. While in Flask 2 (S2), with the addition of 0.5 mg of FeCl2, docosapentaenoic acid was produced. In the last flask which involved the addition of 1.0 mg of FeCl2, more fatty acid was detected. In GC-FID data, 6 types of fatty acids were detected. Linolein acid, linolenic acid, stearidonic acid, docosapentaenoic acid, docosahexaenoic acid and docosanoic acid were produced at different retention times. Most of the fatty acids produced are polyunsaturated fatty acid (PUFA). In transesterification, the fatty acid reacts with methanol and acid catalyst. The reaction produces fatty acid methyl ester. In Flask 1, the control flask, without the addition of FeCl2, no fatty acid methyl esters (FAME) was produced. However, in Flask 2 and 3 which were added 0.5 mg FeCl2 and 1.0 mg FeCl2, n-hexadecanoic acid methyl ester which is also known as palmitic acid was produced. Palmitic fatty acid can be used for biodiesel production.
    Matched MeSH terms: Microalgae
  9. Norlina R, Norashikin MN, Loh SH, Aziz A, Cha TS
    Appl Biochem Biotechnol, 2020 Aug;191(4):1653-1669.
    PMID: 32198601 DOI: 10.1007/s12010-020-03312-y
    Abscisic acid (ABA) has been known to exist in a microalgal system and serves as one of the chemical stimuli in various biological pathways. Nonetheless, the involvement of ABA in fatty acid biosynthesis, particularly at the transcription level in microalgae is poorly understood. The objective of this study was to determine the effects of exogenous ABA on growth, total oil content, fatty acid composition, and the expression level of beta ketoacyl-ACP synthase I (KAS I) and omega-3 fatty acid desaturase (ω-3 FAD) genes in Chlorella vulgaris UMT-M1. ABA was applied to early stationary C. vulgaris cultures at concentrations of 0, 10, 20, and 80 μM for 48 h. The results showed that ABA significantly increased biomass production and total oil content. The increment of palmitic (C16:0) and stearic (C18:0) acids was coupled by decrement in linoleic (C18:2) and α-linolenic (C18:3n3) acids. Both KAS I and ω-3 FAD gene expression were downregulated, which was negatively correlated to saturated fatty acid (SFAs), but positively correlated to polyunsaturated fatty acid (PUFA) accumulations. Further analysis of both KAS I and ω-3 FAD promoters revealed the presence of multiple ABA-responsive elements (ABREs) in addition to other phytohormone-responsive elements. However, the role of these phytohormone-responsive elements in regulating KAS I and ω-3 FAD gene expression still remains elusive. This revelation might suggest that phytohormone-responsive gene regulation in C. vulgaris and microalgae as a whole might diverge from higher plants which deserve further scientific research to elucidate its functional roles.
    Matched MeSH terms: Microalgae
  10. Bong, S.C., Loh, S. P.
    MyJurnal
    This study was conducted to investigate and compare the fatty acids and tocopherols of lipid extracted from marine microalgae, Nannochloropsis oculata (NO) and Tetraselmis suecica (TS) using solvent extraction and supercritical fluid extraction (SFE). Fatty acids and tocopherols were determined in the extracted lipid as functions of the temperature (40, 80oC) and pressure (3000, 5000, 7000, 9000psi). Dichloromethane/methanol and hexane were the chosen conventional solvent for fatty acids and tocopherols extraction respectively. The results obtained showed that there were differences in the fatty acid composition of various lipid extracts of NO and TS. Extracts of NO were high in myristic acid (C14:0) (17-35%), palmitic acid (C16:0) (14-47%) and palmitoleic acid (C16:1) (11-42%) whereas extracts of TS were high in C14:0 (21-34%) and C16:0 (29-49%). Eicosapentaenoic acid (EPA) was detected only under certain SFE conditions in NO but was not detected in TS. α-, β- and γ-tocopherol were detected in various SFE extracts of NO but only α- and β-tocopherol were detected in TS. Hexane extraction of both NO and TS resulted in the detection of only α-tocopherol. In conclusion, the use of different extraction methods resulted in different compositions and concentrations of fatty acids and tocopherols in the microalgae studied.
    Matched MeSH terms: Microalgae
  11. Zainul Azlan N, Mohd Yusof YA, Alias E, Makpol S
    PMID: 31428175 DOI: 10.1155/2019/8394648
    Background: Loss of skeletal muscle mass, strength, and function due to gradual decline in the regeneration of skeletal muscle fibers was observed with advancing age. This condition is known as sarcopenia. Myogenic regulatory factors (MRFs) are essential in muscle regeneration as its activation leads to the differentiation of myoblasts to myofibers. Chlorella vulgaris is a coccoid green eukaryotic microalga that contains highly nutritious substances and has been reported for its pharmaceutical effects. The aim of this study was to determine the effect of C. vulgaris on the regulation of MRFs and myomiRs expression in young and senescent myoblasts during differentiation in vitro.

    Methods: Human skeletal muscle myoblast (HSMM) cells were cultured and serial passaging was carried out to obtain young and senescent cells. The cells were then treated with C. vulgaris followed by differentiation induction. The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, PTEN, and MYH2 genes and miR-133b, miR-206, and miR-486 was determined in untreated and C. vulgaris-treated myoblasts on Days 0, 1, 3, 5, and 7 of differentiation.

    Results: The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, and PTEN in control senescent myoblasts was significantly decreased on Day 0 of differentiation (p<0.05). Treatment with C. vulgaris upregulated Pax7, Myf5, MEF2C, IGF1R, MYOG, and PTEN in senescent myoblasts (p<0.05) and upregulated Pax7 and MYOG in young myoblasts (p<0.05). The expression of MyoD1 and Myf5 in young myoblasts however was significantly decreased on Day 0 of differentiation (p<0.05). During differentiation, the expression of these genes was increased with C. vulgaris treatment. Further analysis on myomiRs expression showed that miR-133b, miR-206, and miR-486 were significantly downregulated in senescent myoblasts on Day 0 of differentiation which was upregulated by C. vulgaris treatment (p<0.05). During differentiation, the expression of miR-133b and miR-206 was significantly increased with C. vulgaris treatment in both young and senescent myoblasts (p<0.05). However, no significant change was observed on the expression of miR-486 with C. vulgaris treatment.

    Conclusions: C. vulgaris demonstrated the modulatory effects on the expression of MRFs and myomiRs during proliferation and differentiation of myoblasts in culture. These findings may indicate the beneficial effect of C. vulgaris in muscle regeneration during ageing thus may prevent sarcopenia in the elderly.

    Matched MeSH terms: Microalgae
  12. Jusoh M, Loh SH, Chuah TS, Aziz A, Cha TS
    Phytochemistry, 2015 Mar;111:65-71.
    PMID: 25583439 DOI: 10.1016/j.phytochem.2014.12.022
    Microalgae lipids and oils are potential candidates for renewable biodiesel. Many microalgae species accumulate a substantial amount of lipids and oils under environmental stresses. However, low growth rate under these adverse conditions account for the decrease in overall biomass productivity which directly influence the oil yield. This study was undertaken to investigate the effect of exogenously added auxin (indole-3-acetic acid; IAA) on the oil content, fatty acid compositions, and the expression of fatty acid biosynthetic genes in Chlorella vulgaris (UMT-M1). Auxin has been shown to regulate growth and metabolite production of several microalgae. Results showed that oil accumulation was highest on days after treatment (DAT)-2 with enriched levels of palmitic (C16:0) and stearic (C18:0) acids, while the linoleic (C18:2) and α-linolenic (C18:3n3) acids levels were markedly reduced by IAA. The elevated levels of saturated fatty acids (C16:0 and C18:0) were consistent with high expression of the β-ketoacyl ACP synthase I (KAS I) gene, while low expression of omega-6 fatty acid desaturase (ω-6 FAD) gene was consistent with low production of C18:2. However, the increment of stearoyl-ACP desaturase (SAD) gene expression upon IAA induction did not coincide with oleic acid (C18:1) production. The expression of omega-3 fatty acid desaturase (ω-3 FAD) gene showed a positive correlation with the synthesis of PUFA and C18:3n3.
    Matched MeSH terms: Microalgae/chemistry
  13. Toh PY, Ng BW, Ahmad AL, Chieh DC, Lim J
    Nanoscale, 2014 Nov 7;6(21):12838-48.
    PMID: 25227473 DOI: 10.1039/c4nr03121k
    Successful application of a magnetophoretic separation technique for harvesting biological cells often relies on the need to tag the cells with magnetic nanoparticles. This study investigates the underlying principle behind the attachment of iron oxide nanoparticles (IONPs) onto microalgal cells, Chlorella sp. and Nannochloropsis sp., in both freshwater and seawater, by taking into account the contributions of various colloidal forces involved. The complex interplay between van der Waals (vdW), electrostatic (ES) and Lewis acid-base interactions (AB) in dictating IONP attachment was studied under the framework of extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) analysis. Our results showed that ES interaction plays an important role in determining the net interaction between the Chlorella sp. cells and IONPs in freshwater, while the AB and vdW interactions play a more dominant role in dictating the net particle-to-cell interaction in high ionic strength media (≥100 mM NaCl), such as seawater. XDLVO predicted effective attachment between cells and surface functionalized IONPs (SF-IONPs) with an estimated secondary minimum of -3.12 kT in freshwater. This prediction is in accordance with the experimental observation in which 98.89% of cells can be magnetophoretically separated from freshwater with SF-IONPs. We have observed successful magnetophoretic separation of microalgal cells from freshwater and/or seawater for all the cases as long as XDLVO analysis predicts particle attachment. For both the conditions, no pH adjustment is required for particle-to-cell attachment.
    Matched MeSH terms: Microalgae/cytology*
  14. Ebrahimi Nigjeh S, Yusoff FM, Mohamed Alitheen NB, Rasoli M, Keong YS, Omar AR
    Biomed Res Int, 2013;2013:783690.
    PMID: 23509778 DOI: 10.1155/2013/783690
    Marine microalgae have been prominently featured in cancer research. Here, we examined cytotoxic effect and apoptosis mechanism of crude ethanol extracts of an indigenous microalga, Chaetoceros calcitrans (UPMAAHU10) on human breast cell lines. MCF-7 was more sensitive than MCF-10A with IC50 value of 3.00 ± 0.65, whilst the IC50 value of Tamoxifen against MCF-7 was 12.00 ± 0.52  μg/mL after 24 hour incubation. Based on Annexin V/Propidium iodide and cell cycle flow cytometry analysis, it was found that inhibition of cell growth by EEC on MCF-7 cells was through the induction of apoptosis without cell cycle arrest. The apoptotic cells at subG0/G1 phase in treated MCF-7 cells at 48 and 72 hours showed 34 and 16 folds increased compared to extract treated MCF-10A cells which showed only 6 and 7 folds increased at the same time points, respectively. Based on GeXP study, EEC induced apoptosis on MCF-7 cells via modulation of CDK2, MDM2, p21Cip1, Cyclin A2, Bax and Bcl-2. The EEC treated MCF-7 cells also showed an increase in Bax/Bcl-2 ratio that in turn activated the caspase-dependent pathways by activating caspase 7. Thus, marine microalga, Chaetoceros calcitrans may be considered a good candidate to be developed as a new anti-breast cancer drug.
    Matched MeSH terms: Microalgae/chemistry*
  15. Quraishi KS, Bustam MA, Krishnan S, Aminuddin NF, Azeezah N, Ghani NA, et al.
    Chemosphere, 2017 Oct;184:642-651.
    PMID: 28624742 DOI: 10.1016/j.chemosphere.2017.06.037
    A promising method of Carbon dioxide (CO2) valorization is to use green microalgae photosynthesis to process biofuel. Two Phase Partitioning Bioreactors (TPPBR) offer the possibility to use non-aqueous phase liquids (NAPL) to enhance CO2 solubility; thus making CO2 available to maximize algae growth. This requires relatively less toxic hydrophobic Ionic Liquids (ILs) that comprise a new class of ionic compounds with remarkable physicochemical properties and thus qualifies them as NAPL candidates. This paper concerns the synthesis of ILs with octyl and butyl chains as well as different cations containing aromatic (imidazolium, pyridinium) and non-aromatic (piperidinum, pyrrolidinium) rings for CO2 absorption studies. The authors measured their respective toxicity levels on microalgae species, specifically, Scenedesmus quadricauda, Chlorella vulgaris and Botryococcus braunii. Results revealed that octyl-based ILs were more toxic than butyl-based analogues. Such was the case for bmim-PF6 at double saturation with an absorbance of 0.11, compared to Omim-PF6 at 0.17, bmim-NTf2 at 0.02, and Omim-NTf2 at 0.14, respectively. CO2 uptake results for ILs bearing octyl-based chains compared to the butyl analog were 54% (nCO2/nIL) (i.e., moles of CO2 moles of IL) and 38% (nCO2/nIL), respectively. Conclusively, 1-butyl-1-methylpiperidinium absorbed 13% (nCO2/nIL) and appeared the least toxic, having an absorbance of 0.25 at 688 nm (double saturation at 7 d) compared to 1-butyl-3-methylimidazolium, which showed the highest toxicity with zero absorbance. Accordingly, these findings suggest that 1-butyl-1-methylpiperidinium is capable of transporting CO2 to a system containing green microalgae without causing significant harm; thus allowing its use in TPPBR technology.
    Matched MeSH terms: Microalgae/drug effects*
  16. Nguyen TDP, Tran TNT, Le TVA, Nguyen Phan TX, Show PL, Chia SR
    J Biosci Bioeng, 2019 Apr;127(4):492-498.
    PMID: 30416001 DOI: 10.1016/j.jbiosc.2018.09.004
    Nowadays, the pretreatment of wastewater prior to discharge is very important in various industries as the wastewater without any treatment contains high organic pollution loads that would pollute the receiving waterbody and potentially cause eutrophication and oxygen depletion to aquatic life. The reuse of seafood wastewater discharge in microalgae cultivation offers beneficial purposes such as reduced processing cost for wastewater treatment, replenishing ground water basin as well as financial savings for microalgae cultivation. In this paper, the cultivation of Chlorella vulgaris with an initial concentration of 0.01 ± 0.001 g⋅L-1 using seafood sewage discharge under sunlight and fluorescent illumination was investigated in laboratory-scale without adjusting mineral nutrients and pH. The ability of nutrient removal under different lighting conditions, the metabolism of C. vulgaris and new medium as well as the occurrence of auto-flocculation of microalgae biomass were evaluated for 14 days. The results showed that different illumination sources did not influence the microalgae growth, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) significantly. However, the total nitrogen (total-N) and total phosphorus (total-P) contents of microalgae were sensitive to the illumination mode. The amount of COD, BOD, total-N and total-P were decreased by 88%, 81%, 95%, and 83% under sunlight mode and 81%, 74%, 79%, and 72% under fluorescent illumination, respectively. Furthermore, microalgae were auto-flocculated at the final days of cultivation with maximum biomass concentration of 0.49 ± 0.01 g⋅L-1, and the pH value had increased to pH 9.8 ± 0.1 under sunlight illumination.
    Matched MeSH terms: Microalgae/cytology
  17. Yaakob MA, Mohamed RMSR, Al-Gheethi A, Tiey A, Kassim AHM
    Environ Sci Pollut Res Int, 2019 Apr;26(12):12089-12108.
    PMID: 30827020 DOI: 10.1007/s11356-019-04633-0
    Production of Scenedesmus sp. biomass in chicken slaughterhouse wastewater (CSWW) is a promising alternative technique for commercial culture medium due to the high nutritional content of the generated biomass to be used as fish feeds. The current work deals with optimising of biomass production in CSWW using response surface methodology (RSM) as a function of two independent variables, namely temperature (10-30 °C) and photoperiod (6-24 h). The potential application of biomass yield as fish feeds was evaluated based on carbohydrate, protein and lipid contents. The results revealed that the best operating parameters for Scenedesmus sp. biomass production with high contents of carbohydrates, proteins and lipids were determined at 30 °C and after 24 h. The actual and predicted values were 2.47 vs. 3.09 g, 1.44 vs. 1.27 μg/mL, 29.9 vs. 31.60% and 25.75 vs. 28.44%, respectively. Moreover, the produced biomass has a high concentration of fatty acid methyl ester (FAME) as follows: 35.91% of C15:1; 17.58% of C24:1 and 14.11% of C18:1N9T. The biomass yields have 7.98% of eicosapentaenoic acid (EPA, C20:5N3) which is more appropriate as fish feeds. The Fourier transform infrared (FTIR) analysis of biomass revealed that the main functional groups included hydroxyl (OH), aldehyde (=C-H), alkanes and acyl chain groups. Scanning electron micrograph (SEM) and energy-dispersive X-ray spectroscopic analysis (EDS) indicated that the surface morphology and element distribution in biomass produced in BBM and CSWW were varied. The findings have indicated that the biomass produced in CSWW has high potential as fish feeds.
    Matched MeSH terms: Microalgae/metabolism
  18. Thanh T, Chi VT, Abdullah MP, Omar H, Noroozi M, Napis S
    Mol Biol Rep, 2011 Nov;38(8):5297-305.
    PMID: 21287365 DOI: 10.1007/s11033-011-0679-4
    An initial study on gene cloning and characterization of unicellular green microalga Ankistrodesmus convolutus was carried out to isolate and characterize the full-length cDNA of ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (RbcS) as a first step towards elucidating the structure of A. convolutus RbcS gene. The full-length of A. convolutus RbcS cDNA (AcRbcS) contained 28 bp of 5' untranslated region (UTR), 225 bp of 3' non-coding region, and an open reading frame of 165 amino acids consisting of a chloroplast transit peptide with 24 amino acids and a mature protein of 141 amino acids. The amino acid sequence has high identity to those of other green algae RbcS genes. The AcRbcS contained a few conserved domains including protein kinase C phosphorylation site, tyrosine kinase phosphorylation site and N-myristoylation sites. The AcRbcS was successfully expressed in Escherichia coli and a ~21 kDa of anticipated protein band was observed on SDS-PAGE. From the phylogenetic analysis of RbcS protein sequences, it was found that the RbcS of A. convolutus has closer genetic relationship with green microalgae species compared to those of green seaweed and green macroalgae species. Southern hybridization analysis revealed that the AcRbcS is a member of a small multigene family comprising of two to six members in A. convolutus genome. Under different illumination conditions, RT-PCR analysis showed that AcRbcS transcription was reduced in the dark, and drastically recovered in the light condition. Results presented in this paper established a good foundation for further study on the photosynthetic process of A. convolutus and other green algae species where little information is known on Rubisco small subunit.
    Matched MeSH terms: Microalgae/enzymology*; Microalgae/genetics*; Microalgae/radiation effects
  19. Zulkifly SB, Graham JM, Young EB, Mayer RJ, Piotrowski MJ, Smith I, et al.
    J Phycol, 2013 Feb;49(1):1-17.
    PMID: 27008383 DOI: 10.1111/jpy.12025
    The green algal genus Cladophora forms conspicuous nearshore populations in marine and freshwaters worldwide, commonly dominating peri-phyton communities. As the result of human activities, including the nutrient pollution of nearshore waters, Cladophora-dominated periphyton can form nuisance blooms. On the other hand, Cladophora has ecological functions that are beneficial, but less well appreciated. For example, Cladophora has previously been characterized as an ecological engineer because its complex structure fosters functional and taxonomic diversity of benthic microfauna. Here, we review classic and recent literature concerning taxonomy, cell biology, morphology, reproductive biology, and ecology of the genus Cladophora, to examine how this alga functions to modify habitats and influence littoral biogeochemistry. We review the evidence that Cladophora supports large, diverse populations of microalgal and bacterial epiphytes that influence the cycling of carbon and other key elements, and that the high production of cellulose and hydrocarbons by Cladophora-dominated periphyton has the potential for diverse technological applications, including wastewater remediation coupled to renewable biofuel production. We postulate that well-known aspects of Cladophora morphology, hydrodynamically stable and perennial holdfasts, distinctively branched architecture, unusually large cell and sporangial size and robust cell wall construction, are major factors contributing to the multiple roles of this organism as an ecological engineer.
    Matched MeSH terms: Microalgae
  20. Rao AR, Sarada R, Shylaja MD, Ravishankar GA
    J Food Sci Technol, 2015 Oct;52(10):6703-10.
    PMID: 26396419 DOI: 10.1007/s13197-015-1775-6
    Effect of isolated astaxanthin (ASX) and astaxanthin esters (ASXEs) from green microalga-Haematococcus pluvialis on hepatotoxicity and antioxidant activity against carbon tetrachloride (CCl4) induced toxicity in rats was compared with synthetic astaxanthin (SASX). ASX, ASXEs, and SASX, all dissolved in olive oil, fed to rats with 100 and 250 μg/kg b.w for 14 days. They were evaluated for their hepatoprotective and antioxidant activity by measuring appropriate enzymes. Among the treated groups, the SGPT, SGOT and ALP levels were decreased by 2, 2.4, and 1.5 fold in ASXEs treated group at 250 μg/Kg b.w. when compared to toxin group. Further, antioxidant enzymes catalase, glutathione, superoxide dismutase and lipid peroxidase levels were estimated in treated groups, their levels were reduced by 30-50 % in the toxin group, however these levels restored by 136.95 and 238.48 % in ASXEs treated group at 250 μg/kg. The lipid peroxidation was restored by 5.2 and 2.8 fold in ASXEs and ASX treated groups at 250 μg/kg. The total protein, albumin and bilirubin contents were decreased in toxin group, whereas normalized in ASXEs treated group. These results indicates that ASX and ASXEs have better hepatoprotection and antioxidant activity, therefore can be used in pharmaceutical and nutraceutical applications and also extended to use as food colorant.
    Matched MeSH terms: Microalgae
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